Wall board



Patented Oct. 1, i 1930 UNITED STATESA PATENT OFFICE soMERLED JOSEPH MeDoNALD, oF GA'rINEAU, QUEBEC, CANADA, AssIGNoR 'ro INTER- NATIONAL FIBRE BOARD, LIMITED, or MONTREAL, QUEBEC, CANADA WALL BOARD Application Afiled December 21, 1928. Serial No. 327,708.

This invention relates to Wallboard and particularly to boards which are made of compressed fibre or like material andus-ed for forming so-called lath for supporting a layer of plaster thereon. Such boards are usually rectangular and are nailed, edge to edge, to the studding of the wooden frames of buildings, a sufficient number of boards being secured in this manner to form the desired area of Wall surface.

Objects ofthe present invention are to provide improved boards in which the edges are so shaped that the boards mutually support one another at the regions where they are not supported by the studding, and that the risk of plaster cracking along the edges of the boards is greatly reduced, and that an approximately air-tight joint is formed between the studding. I

The invention consists in the improved formation and arrangement hereinafter described and more particularly pointed out in the appended claims.

Referring now to the accompanying drawings, which illustrate, by way of example, one convenient embodiment of the invention:

Figure 1 is a front-elevation of a portion of the improved board, showing fragments of other boards engaging the edges thereof;

Figure 2 is a side elevation partly in section on the line 2-2 of Figure 1;

Figure 3 is a side elevation partly in section on the line 3 3 of Figure l;

Figure 4 is a. plan view of Figure 1, and

Figure 5 is a fragmentary section on the line 5-5 of Figure 1.

In the drawings the boards are shown with their edges slightly separated for the sake of clearness of illustration, but actually the edges would be in contact in practice.

In the illustrated examples of the invention the board has flat front and rear surfaces 1 and 2, respectively, and side surfaces 3. The upper edge is formed with a V-shaped or similarly' shaped groove 4 and the lower edge with a complementary tongue portion 5.

Preferably, the front wall of the groove 4 is recessed at suitable short intervals to provide notches 6.

It is also preferred to provide spaced in- `might be lengthened so that the notches 8 could overlap or connect two adjacent notches 7.

It is believed that the manner of mounting the boards in relation` to one another will be clear from F igure 1 of the drawing, in which the four edges of a board A are shown together with the lower part of another board B and the right-hand edge of a third board C.

The number and size of the notches 6, 7 and y 8 may be selected according to the size of board to be manufactured. f

It will be seen that the tongue 5 of each board engages the groove 4 of thel next board below and the V-shapedljoint thus formed enables the boards to' give one another mu- -tual support against lexure, to-which ordinary butting edges would be subject at the regions where the boards are notv supported by the wooden studding. This construction also provides a substantially air-tight joint.

The notches 6 form a series of wedge-like recesses which provide good anchoring or bonding points for the plaster which is afterwards applied to thel front surface of the wall formevd of the boards assembled in the manner described. j i

. The notches 7 and 8 form two lseries of staggered, wedge-like recesses providing improved anchorage or bonding points for the plaster.

The notches 6,7 and 8 serve another important purpose in that` owing to their wedgelike form, they have the effect of advantageously changing the direction of the reaction forces created when rearwardly directed forces are applied to a plastered Wall constructed according to this invention. In a Wall constructed of ordinary boards with plane butting edges, the reaction forces are comparatively feeble and in such a direction that straight cracks in the plaster, along the line of the abutting edges of the boards, are readily made. InV a Wall made up of plastered boards according to the present invention, however, the reaction forces are such that the plaster cannot crack along a straight line, but canonly crack along undulating lines which dip into the notches. As it requires a much greater force to produce such an undulating crack than a straight one, it follows that in walls made ofthe improved boards there is a greatly reduced liability to fracture of the plaster.

The invention is particularly applicable to boards made of compressed fibre, but may be applied to boards of other materials of a similar character.

The foregoing description and accompanying illustration are given by way of example and modifications within the scope of the appended claims may be resorted to without departing from the scope of the present invenl tion.

I claim:

1. A wall comprising a plurality of snniy lar substantially rectangular boards arranged edge to edge in vertical and horizontal rows, the opposed edges of the boards yhaving tongue and grooved engagement with each other and the remaining opposed edges of the boards being straight and in abutting engagement and also having a series of equl-distant Wedge-like depressions to provide binding points.

Q. A wallboard comprising a substantially rectangular sheet of material having in one edge a longitudinal groove, a complementary tongue extending along its opposite edge for engagement with the groove of an adjacent board, the outer wall of the groove being recessed at intervals to the full depth of the groove to provide a series of notches which constitute binding points for plaster applied over the wallboard, the remaining opposite edges of the board being straight and having a series of Wedge-like depressions spaced from each other distances equal to the length thereof with the series'in one edge staggered with respect to the series in the abutting edge of an adjacent board to Jform additional binding posts :tor the plaster.

In testimony whereof I have afliXed my signature.

vSOMERLED JOSEPH MCDONALD. 

